ST. LOUIS (KMOV) -- The St. Louis Convention and Visitors Commission will lose about $6 million after federal General Services Administration abruptly canceled a major conference it was planning to hold at the America’s Center in August.

The GSA, which manages several contracts for many federal agencies, has been under fire since a lavish Las Vegas conference in 2010 cost taxpayers more than $2,700 per attendee.

Since the story broke, several executives were let go and the agency’s standards have been revised.

The new rules led to the agency on Wednesday canceling GovEnergy, a major yearly energy workshop and tradeshow, which was scheduled to go on at the America’s Center from August 19 to 22.

The agency booked 2,500 rooms at 10 downtown hotels.

All attendees, vendors and federal agencies will be reimbursed. But it looks like all hotels will lose the money if the rooms aren’t filled.

The CVC estimates the convention would have generated $6 million, which will not be replaced.

On Thursday, a GSA spokesperson issued this statement:

"After a rigorous review of the 2012 GovEnergy Conference, GSA has postponed this year’s conference because it does not meet the new guidelines that GSA has put in place for conferences and contracts. There were many unanswered questions about how the conference was structured and the contracts, and there was not sufficient time to address the problems raised. We are working hard to make sure that all parties are treated fairly.”

According to a GSA source, the organization has not invoked a "force majeure. Funds will be reimbursed to registrants and vendors, and the GSA will work with the event's contractor in the process. As for questions about cost, the GSA is still in the middle of accessing and reviewing that information.

The GSA has sponsored two major conferences in the past two months that have been widley attended by federal employees and businesses, including: Expo in San Antonio, Texas and Fed Fleet in Louisville, Kentucky.